1. Field of the Invention
The present invention relates to a semiconductor device having a chip-on-chip structure, and to a semiconductor chip for use in such a semiconductor device.
2. Description of the Prior Art
Conventionally, semiconductor devices having so-called chip-on-chip structures have been proposed that are built by bonding a semiconductor chip to the surface of another semiconductor chip. A typical example is an LSI chip, constituting a gate array, having another LSI chip, constituting a memory, analog-to-digital conversion device (hereafter referred to as an A/D conversion device), or CPU, superposed and thereby mounted thereon.
However, in a semiconductor device having a chip-on-chip structure, it is necessary to design a pair of semiconductor chips that are to be bonded together to have pads in corresponding positions. For this reason, to upgrade an existing system, for example by increasing the capacity of a memory, by increasing the number of conversion bits of an A/D conversion device, or by increasing the number of processing bits of a CPU, it is necessary to renew not only the design of the LSI chip constituting such a device, but also the design of the gate array LSI chip to which it is bonded. That is, there is no choice but to develop and produce a completely new product.
This means that, every time a system is upgraded, a large amount of human energy needs to be expended on system upgrading including the modification of the manufacturing line.
An object of the present invention is to provide a semiconductor device having a chip-on-chip structure that allows easy production of various types of semiconductor devices as a whole, and to provide a semiconductor chip for use in such a semiconductor device.
To achieve the above object, according to one aspect of the present invention, a semiconductor device has a first semiconductor chip and a second semiconductor chip superposed on and bonded to the surface of the first semiconductor chip. Moreover, in the region on the surface of the first semiconductor chip where the second semiconductor chip is bonded to the first semiconductor chip, chip connection portions are arranged in standardized positions so as to fit a plurality of predetermined types of semiconductor chips, and, on the second semiconductor chip, chip connection portions are arranged in standardized positions so as to fit the chip connection portions arranged on the first semiconductor chip.
In this structure, on the surface of the first semiconductor chip, chip connection portions are arranged in standardized positions, and, on the second semiconductor chip, chip connection portions are arranged in positions that fit the chip connection portions arranged on the first semiconductor chip. Here, the chip connection portions are arranged in standardized positions in the first semiconductor chip so as to fit a plurality of predetermined types of semiconductor chips, and therefore, as long as the chip connection portions are arranged in similar standardized positions on the second semiconductor chip, different types of semiconductor chips can be used as the second semiconductor chip. In this case, the same first semiconductor chip can be used without modifying the design thereof.
Thus, it is possible to bond various types of semiconductor chips as the second semiconductor chip to the surface of the first semiconductor chip. This makes it easy to produce various types of semiconductor devices, as a whole, having a chip-on-chip structure.
According to another aspect of the present invention, a semiconductor chip has, on the surface thereof, a chip bonding region to which one of a plurality of predetermined types of semiconductor chips is bonded. In this chip bonding region, chip connection portions are arranged in standardized positions so as to fit the plurality of predetermined types of semiconductor chips.
In this structure, the chip connection portions are arranged in standardized positions so as to fit a plurality of predetermined types of semiconductor chips. Thus, there is no need to modify the design of this semiconductor chip to connect any of the plurality of types of semiconductor chips to the chip connection portions to produce a semiconductor device having a chip-on-chip structure.
According to still another aspect of the present invention, a semiconductor chip has a plurality of chip connection portions arranged on the surface thereof in positions standardized among a plurality of predetermined types of semiconductor chips.
In this structure, the chip connection portions are arranged in standardized positions so as to fit a plurality of predetermined types of semiconductor chips. Thus, there is no need to modify the design of this semiconductor chip when another semiconductor chip having chip connection portions arranged in standardized positions corresponding thereto is bonded thereto. This makes it easy to produce a plurality of types of semiconductor devices having chip-on-chip structures.